Seed coat permeability in semi-hard snap bean seeds: its influence on imbibitional chilling injury

Abstract

SummaryThe susceptibility of a snap bean (Phaseolus vulgaris) breeding line with the semi-hard seed (SHS) characteristic to imbibitional chilling injury was studied. SHS with greater than 10% initial moisture content imbibed water readily. However, at 6% and 8% moisture levels 18 and 6 days were required for full imbibition, respectively. Seed coat permeability of SHS was readily reversible and was moderated by the seed storage relative humidity. Seeds of cv Bush Blue Lake 47 and cv Burly and SHS were adjusted to 12% moisture, and found to be tolerant to imbibitional chilling injury. At 8% moisture only SHS was not susceptible to chilling and this was attributed to slow hydration rates. Mechanical damage of SHS with 8% moisture resulted in increased hydration rates, solute leakage and chilling injury. An improvement in field seedling emergence was measured for SHS compared to the Bush Blue Lake 47 and Burly. SHS exhibited good field emergence at both 8% and 12% moisture.